Golf beginners or golfers who try to adapt to an uneven field have difficulties in taking an address posture, which is the most basic element of golf.
Golfers should be positioned at address such that a target point is perpendicular to a golfer's point of view. However, the angle is not readily perpendicular and tends to be slightly deflected, and in such a posture, golfers hit the golf ball out of the target point.
In particular, golfers tend to address the ball in a completely wrong direction because of an uneven field or an optical illusion caused by the surrounding environment.
Therefore, an apparatus intended to aid a golfer in maintaining a correct address posture even in varying surroundings is required.